A Good Cause
by OrbitZero
Summary: An MCU AU set during the events of Endless Waltz. Told in bits and pieces instead of one complete story. 1: Heero and Duo have made it into X-18999. As Duo fixes the colony's orbit, Heero finds himself evenly matched against a mysterious opponent.


This is a Marvel Cinematic Universe AU, but the characters of MCU are not involved, only their features. I don't know what I'm doing but I hope it's fun. u_u I know I don't have the time to write the whole story for this so I'm just being entirely self-indulgent and writing the parts I want most to write. :) Maybe someone else could enjoy them too. And of course, I have stolen directly something from one of the movies, one little thing at the end here...

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The lights in the corridors flashed red, alarms blaring out their warnings. The stability of the colony's orbit around its Lagrange point was degrading quickly and he felt like he couldn't move fast enough. The Earth, for all the flaws of civilization, didn't deserve the kind of turmoil and carnage Dekim intended to unleash on it, no matter what cause he thought he might be accomplishing. And then there was Relena to think of. She was being held hostage but he knew she wouldn't just be whimpering in a room, fearing for her life. She'd be working whatever angle she could to try to talk Dekim's seven-year old figurehead out of this. Heero couldn't say how effective her attempts would be. If there was anything Dekim was good at, it was shaping the formative and malleable minds of children, turning them into whatever monsters he needed to fight his battles for him.

Monsters like himself.

He'd never felt any kind of loyalty to Dekim. Maybe hatred was really the best word for what he felt for the man. He'd been given up by his father to become Dekim's pet project, a perfect soldier. The very fiber of his being had been tampered with to make him stronger, faster, more durable, basically inhuman. He was an army in and of himself, even if he didn't look it in his blue jeans and navy jacket. But for all the conditioning Dekim had tried to warp his mind with, it ended up undone the longer he spent away from the man and in the company of people he'd eventually come to call friends.

That notion would've seemed absurd to him just two years ago. He believed so fully that his purpose in life was singular-to eradicate the threat of OZ to the colonies. But that idea was challenged as he met the same people again and again in the course of that war until he had no choice but to accept that he'd changed. He was no longer a lone child soldier with a code name and a war machine and a single mission. He was Duo calling him a 'god damn loony toon' before he accomplished some superhuman feat. He was Wufei's easiest opponent in chess because he'd never been taught to see the long-reaching effects of his actions-that responsibility was left to his superiors. He was Quatre giving reassurance without obviously doing so because he knew Heero was not used to getting it. He was Relena's firsthand glimpse of war and love all at once even if he didn't really know what that meant. And he had been a series of conversations each the length of a burning cigarette because of all the other pilots he and Trowa knew war the most intimately. Maybe that was why Trowa let it kill him. For a good cause. Soldiers always died for good causes and everyone's luck ran out sometime. Heero never blamed Quatre for what happened, but that didn't stop Quatre from carrying the guilt.

So if soldiers fought for causes, ending Dekim's threat to the Earth would be his. He'd started out as a terrorist sending a message. And now his purpose had changed, fractured into many purposes, and protecting the Earth was his priority now. He had only to rendezvous with Duo in the colony's control room to nullify the biggest immediate threat to the planet. And after that?

He was still getting better at mapping out the future. But he was certain Relena needed him. In some battles, the kind of brute strength and endurance he had in spades was the only thing necessary for victory. Winning others relied on words and a strength of a different kind. Something he didn't have. But she did. So in some way, he-and the Earth-needed her, too. He would save her from her captors, and she would save everyone from another war. He could deduce that destabilizing the colony at this juncture was Dekim's way of keeping Duo and Heero too busy to get to Relena. They were probably dragging her off to some other location as he and Duo worked. But he'd find her, one way or the other.

There were obstacles. Of course there always were. Wufei had defected, faced a question too big for him to answer on his own and he'd looked here for help. Heero couldn't say if he thought this was a permanent change or not. Whatever the reasons, this left him no choice but to treat Wufei as the enemy for now. Maybe they could change his mind in time. After this was all over, Wufei might surrender. He could only hope it wouldn't come down to something worse than that.

" _I'm in,_ " came Duo's voice in his ear. He was able to get to the control room a lot quicker. Growing up a thief on the streets of a colony in L2, Duo came into his own as a stealth expert, good at slipping into places he shouldn't be. Obviously Howard's suit helped a lot, since it could shrink him down to be about the size of an ant. That's what Duo called himself when he had to wear it, a self-deprecating grin on his face as he spoke the title he'd given himself. Heero saw the value in a more secretive approach to a target, but was a much more blunt person. He had no idea if that was a result of his conditioning or not.

"ETA eight minutes," Heero answered back.

" _You know, you could say something a little more 'two buddies on a job', a little less 'google maps giving directions'. Like, 'be there in a jiff!'"_

"A 'jiff' is not a specific unit of measurement, and it wouldn't be very helpful."

Duo sighed. Heero knew his behavior got on the other pilot's nerves sometimes but he found it amusing in his own way. Besides, it wasn't as if Duo was always the easiest person to work with. Heero didn't dislike him by any means, but they were, simply put, very different. " _You know if you punch your way right through the walls you'd cut a much more direct path. Seeing as you're so into efficiency and all that."_

"Noted," he said and Duo was silent for the moment. Something Heero would later be grateful for. He needed all of his focus when he turned the corner and was met with the barrel of a gun in his face. While he and Duo-with Sally and Noin's help-had cut through dozens of MS just to get into the colony, it'd been fairly easy once they were inside. Wufei had been their last significant line of defense to overcome, but they'd managed to shake him. Or he was called away. Heero couldn't decide which it was. Either way, as Duo liked to say, 'it'd been smooth sailing'. Until now.

Heero grabbed the wrist holding the gun, inhumanly quick reactions coming to his aid again. The bullet hit the roof and his ears rang. His opponent's knee came up into his gut and Heero's breath left him. The struggle for the gun continued, and now it fired at the floor, bullet ricocheting and nicking him on the back of the calf. He drove an elbow into the guy's rib cage, putting them on equal footing as far as their lungs were concerned. Heero kept his iron grip on that wrist, trying to keep control of the biggest threat in the fight. His opponent smashed his other fist into the side of his head, the blow impossibly hard and leaving Heero with blackness at the edge of his vision. He didn't let it slow him down. Few things did. He kept his focus in one place for a brief moment-about where the guy's eyes must be behind the visor of the helmet.

The colony's gravity cut out in time with the flickering of the lights, and both pairs of feet left the ground. He ground his teeth, knowing this meant they were running out of time to re-stabilize the orbit. There was a split-second between them as they both tried to arrange themselves in the more advantageous position in the sudden zero-g environment. Heero came out on top and managed to kick the gun out of the guy's hand. It spun away down the corridor. He drew up his legs, planted the soles of his feet in the nearest wall, and used that momentum to spin them around to face the opposite direction. The other guy tried to separate himself, but Heero shoved his feet into his chest and they flew away from each other. Heero drew his own gun and fired twice, each shot driving him back a little further until he hit the wall. He heard the bullet ricochet again but off of what? That shot was dead center of the man's chest. He snatched the still spinning pistol out of the air and fired both of them.

It was the left arm. Under the flight suit, there had to be some kind of metal. Maybe a thin layer of metal armored the suit. But then how could he move so fluidly if his suit was laced with unyielding metal that would seriously restrict his range of motion?

There was a slight screeching noise when the other guy dug his fingers into the ceiling of the corridor to steady himself. Bright sparks caught his eye. The momentum Heero had created terminated when the guy's body swung up, back meeting the ceiling with a thud. Now he could clearly see gleaming metallic fingertips peaking out of the glove on the left hand, bright spots beneath the black flight suit where the bullets shaved away the cloth. Heero was no stranger to those kinds of enhancements. He had plenty of his own, only they were the changes embedded in his very DNA instead of anything external. So it came as no surprise that Dekim, the same man who'd funded what happened to Heero, would toy with other people's lives in whatever way best fit his designs. He wondered briefly if the other soldier was like him, an orphan snatched up for experimenting on. Or maybe he was one of the thousands of people who actually wanted Dekim for their leader.

Duo's voice crackled in his ear, " _Heero, where are you? It's crunch time, buddy, and I hope I don't end up meaning that in a literal way!"_

"I'll be there," he responded. He couldn't abandon the fight to have the soldier follow him but he couldn't ask Duo for back-up and tear him away from repairing the colony's orbit. He knew ultimately that if push came to shove, Duo could fix the orbit on his own. It'd just be a little more difficult for him. So Heero had to end this himself, and he had to do it quick. He shoved off the wall, and at the same time, the other guy pushed himself away from his corner of the ceiling. Duo apparently managed to get the colony spinning, and he could feel gravity tugging him down again. Heero hit the ground feet first. The other held out his hands, pushed off the floor, and twisted in mid air to gracefully land facing Heero. _  
_

A knife flashed and the guy dashed forward. Heero shifted just out of the blade's path and he felt it break the fabric of his jacket. He gripped the other's wrist again, this time twisting his right arm around to try to nullify the threat of the knife. The guy put all his weight into Heero, flipped himself over his back and slammed his left fist into Heero's stomach. The hold broke. Heero had less than a second to react, so he did. Again the knife slid just by him, biting the air beside his cheek. He kicked hard in response, foot meeting the guy's sternum. His opponent stumbled back, but not without another swipe of the blade. It drew blood from Heero's shin, but not enough to stop him. He grunted when he was caught by the throat, felt that hand crushing his windpipe, and without the breath to spare, he pulled his legs up for another kick. His heels came down on the visor. It cracked and the guy's head snapped back. He kicked again, and his chest burned as hard metal fingers sank into his skin. He kicked one more time and the man dropped him, stumbling back.

Heero hit the ground hard but took in a breath as he rolled away from a booted foot coming down to smash his nose into his face. He fired another bullet. It scraped by the black flight helmet and Heero ground his teeth. Fights rarely lasted this long for him, save when he was faced up against the other pilots. The enemy responded to the gunshot by throwing the knife. Heero had no choice but to shove himself backwards and the knife sank into the ground about where his stomach had been. He dove for the knife, got his fingers around the handle, but his opponent took hold of his wrist and tried to drive the blade back into Heero's throat. It seemed almost impossible to hold back the guy's left arm, even for him, but he planted his feet firmly, gripped it tightly by the wrist with his free hand. The end of the blade hovered just a hairsbreadth from his throat. He could practically envision the other's teeth grinding together with effort as he tried to close the insignificant gap and end the fight.

There was a somewhat familiar noise and a loud whoop and suddenly his opponent was on his back. Duo had dragged him down to the ground before zipping away again, too small to see. Heero held up his arms in a defensive position as the other guy jumped back to his feet. But he was cautious, scanning the corridor for Duo.

 _"Why didn't you just say you needed help?"_ Duo asked over the radio.

"The colony?" he said, keeping his eyes trained on that blade, searching for the slightest coiling of muscles to indicate any movement.

" _It's safe for now. Let's drop this guy and get out of here."_ Just as Duo finished speaking, he appeared again, sailing through the air and slamming a fist into the side of the helmet. The guy swung his knife but Duo was already too small to see again and it just sliced through the air. Heero dashed towards him, ducked the knife, and swept out a leg to trip him. Predictably, his feet came up as he flipped back and as one of his hands met the metal floor, Duo reappeared, feet meeting his exposed back before he disappeared again. The knife skittered away and Heero stopped it beneath his boot. The guy slid along the ground until he slammed the metal fist into the floor to stabilize himself.

 _"Shit!"_ Heero heard Duo cry out but he didn't inquire of his position. Couldn't give anything away to the enemy and if Duo was talking, he was probably okay. " _I don't know if I've just never explicitly said this, but next time?_ Tell me _when I'm fighting a dude who can put a hole through a metal floor with his bare hands!"_

"Roger that," Heero said instead, just to show Duo he heard him. The opponent apparently took it as a synchronization of an impending attack, and he tensed. Almost as some desperate or angry last resort, the guy tore off his helmet and tried to smash it into Heero's face. It caught a stunned Heero in the jaw and he stumbled back, unable to keep from staring. He was on a mission and he was supposed to be composed, focused, and exact. But he wasn't prepared for this and he couldn't keep himself from saying his friend's name when he saw his was the face under the helmet. His friend who'd been dead for over a year.

But the other guy drew his brows together in plain, almost irritated confusion and he simply asked, "Who the hell is Trowa?"


End file.
